The NT File System, introduced with WindowsNT and later modified in Windows 2000 to support compression. It was further enhanced in XP, 7, etc., but not that much – most of the new features (like encryption) have caused more trouble than they’re worth.

There has long been an open-source effort spanning a number of operating systems that has recently gone commercial and seems to have reached some sort of understanding with Microsoft regarding the IPR involved.

Paragon has long had a commercial driver that integrates (very) smoothly1 with the OS, including adding the appropriate options to Disk Utility for formatting disks and partitions.

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1Which is why I ended up buying a license of their 7.0 software for one of my Snow Leopard machines. Your mileage may vary.